The invention relates to synchronous motors, of the type comprised of a pair of stators surrounding an armature having circumferentially successive armature poles of alternate polarity. In the type of motor in question, each stator is comprised of a first pole teeth plate and a second pole teeth plate, with the teeth of the first plate of each stator being interdigitated with the teeth of the second plate of the same stator and extending generally in axial direction of the motor, radially outwardly of the armature but radially inwardly of the stator winding. The angular spacing between a point on a pole tooth of the first plate of one stator and the corresponding point on the neighboring pole tooth of the second plate of the same stator constitutes one pole pitch. In the type of motor in question, the stators are arranged coaxial to each other, but offset relative to each other by half the pole pitch.
With motors of the type in question, the use of two stators angularly offset relative to each other by half the pole pitch creates the possibility that the motor armature per rotation will perform a number of steps twice as large as the number of pole teeth of a stator. With one known arrangement, the angular offset of the two stators relative to each other is established by using a housing which serves to receive the two stators. The housing is provided with grooves angularly offset relative to each other by half the pole pitch. The stators are provided with projections which are received in respective grooves, to thereby establish proper relative angular positions for the two stators.